1. Field of the Invention
The present invention relates to a system and method of tying down a roof structure of a building to prevent the roof structure from blowing off during a severe storm, and more particularly, to a system and method for strapping down a roof assembly such that uplift pressures to the roof assembly are transferred to the foundation of the building during a severe wind storm.
2. Description of the Related Art
During a storm with severe winds, such as a hurricane, a roof structure made of individual, interconnected roof materials is likely to detach from a building. Examples of such roof structures include metal pan roof structures on commercial/industrial buildings and roof structures on some residential buildings, such as mobile homes. For roof structures with individual, interconnected roof materials, such as metal pans, the bottom pan of each individual roof material is typically face screwed to the top of the building's sheathing or structural support frame and the individual roof materials are interconnected with various pre-existing interlocking design systems.
When a metal pan roof system is exposed to extreme winds, such as hurricanes or tornadoes, un-repairable damage is likely to occur when fasteners attaching the metal roof panels to the structural frame fail. The fasteners typically fail under pressure differentials (lift) created by airfoil (vacuum), as a consequence of high velocity winds over the surface of the roof compounded by high velocity of winds entering the structure. This causes wind capture which is the development of an internal pressure to the underside of the roof panels.
There is currently no system for tying down roof structures with individual interconnected roof materials. Due to the lack of appropriate systems for strapping down these roof structures, insurance companies typically hesitate to insure buildings with individual interconnected roof materials.